I have been reading alot about bonding instead of welding. I have a project I'm working on now and i would like your advice. It's a 1967 Camaro that had a lot of rust. All new sheet metal except floors and trunk floor even a new roof panel. Would you bond the quarters and roof or weld? I have never bonded anything before.
Thanks,
Rusty

On something like the quarter you would want to weld some of it, like the sail panel where you could "see" the seam. The wheel well is a perfect place to bond. I regularaly hang quarters and the wheel well is the only place I bond.

The roof panel? That s a perfect bonding panel. You could bond the whole thing (many cars roofs these days are bonded). One plug weld at each corner is all you would need. I highly recommend bonding it.

Here is a GM bulletin on bonding a repair piece on an SUV roof. This particular bulletin is interesting in that they even recommend bonding the seam that will be "seen". This will usually cause a "ghost line" showing up thru the filler you have used to smooth it out and is not recommended. So I was surprised to see that GM would recommend it. They do give a special instruction for doing that seam though.

Anyway, it will give you an idea of how these products are used.
Brian

I can see bonding a late model roof panel, but not an early camaro.
The front and rear edge is attached at the pinch weld area in the windshield and the rear glass. This is a rather rough area and is not very smooth. It would be very hard to get it clean enough to bond also there is not very much area there about, 1/2 inch. Even the drip rail area is not very suited for bonding.

The top of these camaros are subject to a lot of stress, as the top more or less takes the place of the frame on full frame cars. I've seen some that flexed enough to crack the glass and crack the quarter at the lower rear edge of the window opening.

I have to tell you Troy, honestly, that Camaro roof is not subjected to any more stress than any other car. The cracks you see on the quarters at the corner of the glass is from the quarter flexing from shutting the door, not from the roof flexing.

Many unibody cars have bonded roofs, the Saturn for instance.
WAY too much is put on the "flexing" angle. The car just doesn't flex that much.

The funny thing is, bonding INCREASES the rigidity. Spot welds flex, the bonding leaves no gaps throughout the length of the bond.

Troy, I know it sounds like a "funky" way to do it when welding is the "real deal". But if you start looking you will see that there are things bonded all over that are subjected to a heck of a lot more stress than that Camaro roof. Planes, (F117A for instance) have structual componants bonded, EVERY Vette ever made has an entirely bonded body. It is everywhere, and when they can find the way to speed up the cure cars won't even be welded anymore at the factory. From what I understand there is a new Jag model that has bonded frame rails. The future is now.

Hey guys, I've been in the body and auto business a long time.
I've been bonding panels on new cars for several years. I knew as soon as I posted that both of you would jump on me as usual, what the heck? Other people here know as much as you two do, as many are professional body men to.

?????????????????????????????????????????????????? _________________________________________________
I have to tell you Troy, honestly, that Camaro roof is not subjected to any more stress than any other car. The cracks you see on the quarters at the corner of the glass is from the quarter flexing from shutting the door, not from the roof flexing
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Cut the top of and jack up one corner, you will see how much flex
or stress there is in that section of the body, as there is nothing to hold it except the flat floor pan.

The cracking at the quarters is caused from torque, on those cars if you stand beside one of them doing a good burnout and tire cleaning, you will see wrinkles at that location. I've seen some of the big boys that wrinkled the top panel on launch, thats called torque. The later model cars are built with more integrity in there unibody design, the early ones were not built that way.

And I agree that bonding if done right on some early camaros that see only light duty will hold alright. (on some panels). I would hate to see someone that has never done any panel bonding attempt to bond a top on one of those cars.

Troy, no one attacked you, all just stated fact for their case.
If we knew you were talking about a dragster may have been a difference response. I have never had a 67-69 that powerful, so I can't say?
Happy Valentines day!

My goodness, this isn't the first time this has happened and it still amazes me. If what Barry or I said "jumping on you" in your world, wow, you must live a pretty cushy life.
I would like to have an intellectual exchange with another bodyman, we both may learn something, but I see that may take some time. I know, I KNOW that if you and I were standing around a shop we could carry on that conversation. I mean, I have been doing that my whole life and have never had a fist fight yet over something as inane as this.

Troy, honestly, I would love to carry on a decent exchange with you but I don't see how that is possible. Let's just say the following statements are not directed towards you. I just want to talk to myself out loud for the next few statements.
If anyone else would like to discuss what Troy and I have said we can do that.

I have seen many cars including the Camao have this crack down the side of the quarter at the rear of the quarter window. VW Beetles get a similar crack right behind the door under the "B" pillar. If you stand to the side and shut the door on one of these hard top bodies you will see the whole front of the quarter flex in. Being the support for the quarter "starts" at the end of the quarter window, this is a weak point. Picture a five foot long piece of 1/8" flat stock in a vice. Clamp it in the vice at about six inches. Now, push and pull on that four and a half foot of flat stock about a thousand times and it will break at the vice,right where it is being held from flexing. THAT is how the quarter cracks on the Camaro. IF the twisting of the body were to crack the body like Troy is thinking, the crack would be going horizontally rearward. I have seen these cracks on six cylinder street cars for years, it has nothing to do with torque. My own 65 Skylark HT (stone stock 300 cid twospeed auto 2.56 gear one legger) had a cracked drivers side quarter right in the same spot. You could see the quarter flex in when you shut the door.

The test on Camaro body by cutting off the roof could be done on any one of a number of cars in fact, most every car. Even with a full frame. My 65 Gran Sport conv with a full boxed frame will flex enough so you can't open the doors.

No, bonding the roof on that Camaro would not be one bit different than a late model car. In fact, I have to assume that the Camaro is stiffer than a 2000 Saturn SL1 which has a bonded on roof skin. But that is only opinion, being I haven't done any testing.

You guys are stretching things a little here. I never said anything about a fist fight or a dragster.

I have been building and restoring and racing early camaros for as many years as you are old. Hundreds of them.

I have fixed many cracks on Monday after a week end of street racing. These cracks go from the lower rear corner of the quarter glass opening toward the end of the rear bumper on the drivers side only. If the door caused the cracks there is something wrong with the quarter post. I've never seen it happen. And I admit there is a lot of things I've never seen yet.

My 69 chevelle conv has never flexed enough to bind the doors.
Even jacked up at one corner.

Marten you know that every time I post, you come on and tell me I'm doing it wrong. Just because I'm not doing it like you do.
I may be doing it wrong, but it certainly worked for me. As I don't have to work any more, unless I want to.

Troy, "everytime", come on now. Listen, we will just have to agree to disagree on this one. I'm still sorry I didn't stop by to say hi when I was in Ark. Maybe one day I'll be living in Altus and we can get together.

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